1. Technical Field
The present invention relates to a display medium and a display device.
2. Related Art
A display medium is known that uses an electrochromic dye (“EC dye”), which reversibly changes a light absorption of a material due to an electrochemical redox reaction. This display medium may include a structure in which an EC dye-containing thin layer and an electrolyte liquid or an electrolyte layer are laminated, or a structure in which an EC dye is dissolved in an electrolyte liquid, between transparent electrodes. When a voltage is applied to the laminated EC dye-containing thin layer and the electrolyte layer via transparent electrodes, the entire surface of the EC dye-containing thin layer undergoes a reversible coloring or color-fading reaction due to the electrochemical redox reaction.
In the display medium using an EC dye, a clear display substantially independent of a viewing angle even under strong outdoor light can be obtained because the image display has a low drive voltage, an excellent image retentivity and is light-absorptive. For this reason, the display medium using an EC dye has excellent characteristics as a glare-resistant mirror for automobiles and light-control glass. Further, the display medium using an EC dye does not require a polarizing plate, and has excellent visibility since the display medium is light-receiving and does not depend on a viewing angle. The display medium using an EC dye also has a simple structure, so it is easy to increase its size. Furthermore, a variety of color tones can be obtained by appropriately selecting EC dye-containing thin layers, and a static display can be achieved simply by interrupting the movement of electrons to maintain a redox state. Moreover, in the display medium using an EC dye, electrical power is not required to maintain the display in a static state, which confers various advantages such as lower power consumption.